Acoustical diaphragm



March 27, 1962 w W HAERTHER, JR 3,026,958

ACOUSTICAL DIAPHRAGM Filed NOV. 25, 1957 F157 /Z )7% @z- ,United StatesPatent 3,026,958 ACOUSTICAL DIAPHRAGM William W. Haerther, Jr., Geneva,Ill., assignor to Hawley Products Company, St. Charles, Ill., acorporation of Delaware p Filed Nov. 25, 1957, Ser. No. 698,823

4 Claims. (Cl. 181-32) This `invention relates in general to acousticaldevices and, more particularly, to improved types of sound reproducingdiaphragms.

It is a primary object of this invention to enable a4 novelsoundproducer or reproducer to be afforded, which will have a substantiallyeven response curve, where all soundsfof the audible range will beproduced or reproduced with substantially equal efficiency.

Another object of this invention is to provide a novel diaphragm capableof reproducing both high and low frequency notes corresponding inintensity, timbre mellowness, and other qualities with the originallyproduced sound. waves. i

Another object'is to enable a novel, effective sound reproducingdiaphragmvhaving a rectangular. shape to be afforded. v

Yet another object of the present invention is to afford a novelrectangular-shaped diaphragm of the aforementioned type wherein thevibratile portion is constructed in a novel and expeditious manner.

- A further object is to provide a novel rectangularshaped diaphragmwherein Vthe vibratile portion has a novel cup-shaped construction.

Another object is to provide aV novel rectangular soundreproducingdiaphragm, the parts of which are constituted and arranged lin a noveland expeditious manner.

Yet another object of the invention i-s to enable av novel rectangular,sound-reproducing diaphragm having the aforementioned characteristics tobe afforded, which is thin and light in weight.

Another object is to enable a novel and practical diaphragm ofsubstantially rectangular shape to be afforded,V

which has a large frontal area and provides good soundreproducingcharacteristics.

A further object of the present invention is to aiford a novel diaphragmof the aforementioned type wherein the vibratile portionthereof iseffectively responsive, as a unit, to both high and lowfrequencyvibrations.

Other and further objects ofthe present invention will be apparent fromthe following description and claims, and are illustrated in theaccompanying drawings which by way of illustration show a preferredembodiment of the present invention and the principles thereof, and whatis now considered to be the best mode in which it is contemplated toapply these principles. Other embodiments of the invention embodying thesame or equivalent principles may be used, and structural changes may bemade as desired by those skilled in the art without departing from thepresent invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a rear elevational view of a diaphragm embodying theprinciples of the present invention;

FIG. 2 is a longitudinal sectional View taken substantially along theline 2-2 in FIG. l;

FIG. 3 is a transverse sectional view taken substantially along the line3-3 in FIG. 2;

FIG. 4 is a transverse sectional view taken substantially along the line4-4 in FIG. 2;

FIG. 5 is a transverse sectional view taken substantially along the line5-5 in FIG. 2;

FIG. 6 is a transverse sectional view taken substantially along the line6--6 in FIG. 2; and

FIG57 is an enlarged detail sectional view taken substantially along theline 7-7 in FIG. l.

A diaphragm 1, embodying the principles of the present invention, isshown in the drawings to illustrate' the preferred embodiment of thepresent invention. i

In general, the diaphragm 1 embodies a concave vibratile portion 2connected by an undulated portion 3 vto a substantiallyrectangular-shaped supporting tiange or rim 4, disposed outwardlythereof 'and adapted to be clamped between the supporting braces, or thelike, of -a speaker, not shown. t

The vibratile portion 2 is of a convex-rearwardly shape, flaringgenerally outwardly and forwardly from a tubularshaped nipple 5 at thecentrally located apex thereof to a substantially rectangular-shapedbase 6 having two parallel short ends 7 and 8 connected by two parallellongitudinally extending sides 9 and 10, disposed substantiallyperpendicular thereto, FIGS. l, 2. and 3.

'Ihe diaphragm 1 is of one-piece construction, and may be made of anysuitable material such as, for example, accreted ibrous material.

The vibratile portion 2 of Vthe diaphragm 1 which, it will beremembered, is generally convex-rearwardly in shape, embodies a smooth,sloping construction from the nipple 5 outwardly and forwardly to allsides of the base 6, FIGS. l-6. 'Ihe depth of the cup-shaped vibratileportion 2 gradually decreases in a substantially straight line along thelongitudinal center line'ofl the diaphragm 1 from the nipple 5 to bothof the ends 7 and 8, FIG. 2. Throughout its length, the vibratileportion 2 of the diaphragm 1 decreases in depth from the longitudinalcenter line thereof outwardly toward the side edges 9 and 10, as shownin FIGS. 3 to 6, inclusive. At the longitudinal center of the diaphragm1, the depth of the vibratile portion 2 decreases, transversely from thelongitudinal center line thereof to the side edges 9 and 10, alongsubstantially straight, relatively steep lines, FIG. 3. From the nipple5 longitudinally outwardly toward each of the ends 7 and 8, the depth ofthe vibratile portion 2 diminishes, transversely to the length thereof,at a graduallydecreasing rate between the longitudinal center linethereof and the longitudinal sides 9 and 10, FIGS. 4 and 5 and 6. Thus,the slope of the sides of the vibratile portion 2 outwardly of thelongitudinal center lineY thereof, gradually diminishes from asubstantially frusto-conical shape, FIG. 3, through an elliptical shape,FIG. 4, a substantially semi-circular shape, FIG. 5, -to a `gentlyrounded shape, somewhat less than semi-circular, adjacent the ends ofthe vibratile portion, FIG. 6i. With this construction, the body of thevibratile portion 2 is curved and tapered in substantially alldirections, While affording a relatively deep concavity from the frontthereof and a relatively large frontal area, to thereby afford a strong,relatively rigid vibratile portion which tends to vibrate as a unit, andwhich is well reinforced against independent movement or flapping of theend portions thereof.

The sides 7-10 of the base 6 of the vibratile portion 2 terminate inedge portions 11 which project forwardly, FIGS. 2 and 3, and the frontedge portions thereof are attached to the inner edge of the continuousundulated portion 3, which extends therearound and which projectsoutwardly therefrom in a direction generally perpendicular to thelongitudinal axis of the nipple 5. The ange 4 is also continuous and isuniplanar, projecting outwardly from the undulated portion 3 in a planesubstantially perpendicular to the longitudinal axis of the nipple 5. Y

With this construction, the diaphragm `1 may be mounted in a speaker, orthe like, with the flange 4 clamped between the supporting braces, orthe like, of the speaker, not shown, and with the vibratile portion 2resiliently mounted on the undulated portion 3 in spaced relation to thediaphragm-supporting portions of the speaker and yto the body of thespeaker, so that the vibratile portion 2 is free to vibrate within thespeaker.

Four openingsn 12 are formed in the outer edge portion of the undulatedportion 3 and the inner edge portion of the ilange 4, adjacent to, butin outwardly spaced relation to the corners 13 of the base 6 formed bythe intersection Vof the sides 7-10 thereof, FIGS. 1 and 7. As isdiscussed in greater detail in my copending application for UnitedStates Letters Patent, Serial No. 698,467, filed November25, 1957, nowPatent No. 2,962,109, the openings 1 2 tend to prevent the diaphragmfrom cracking and breaking out at the corners and, it is believed, tendto prevent the end portions and longitudinal side portions of thediaphragm 1 from vibrating relative to each other, so that a diaphragmis afforded which is structurally strong and embodies good tonereproducing characteristics.

' In the formation of the diaphragm 1, the tubular-shaped nipple isnormally formed with a cap portion 14 closing the rear end thereof, and,as shown in FIG. 2, this cap portion may be clipped or otherwise removedtherefrom prior to mounting the diaphragm 1 in a suitable speaker, orthe like.

It has been found that with the diaphragm 1 constructed'in accordancewith the disclosure herein, the structural strength of the vibratileportion 2 is so distributed that the latter portionv tends to vibratesubstantially as a unitn on the undulated portion 3a` by which it isconnected to the flange 4, when driven by suitable members such as, for.example, the voice coil of a dynamic speaker connectedto the nipple 5 ofthe diaphragm 1. With this construction, when the diaphragm 1 is mountedinthe' aforementioned manner in a speaker, remarkably true reproductionof sounds is afforded thereby.

Acoustical diaphragms of substantially rectangular shape have a numberof advantages over diaphragms of other shapes such as, for example,conical diaphragms.

Thus, while the preferred embodiment of the present invention has beenillustrated and described herein, it is to be understood that this iscapable of modification and Y tion to said tubular nipple.

2. An acoustic diaphragm of the type defined in claim l, and in whichsaid vibratile portion is substantially the same width throughout itslength, and longitudinally slopes from a substantially frusto-conicaltransverse crosssectional shape at said nipple through a substantiallyelliptical transverse cross-sectional shape, and then a substantiallysemi-circular transverse cross-sectional shape, to a rounded transversecross-sectional shape of less depth than a semi-circle. v 3. An acousticdiaphragm of the type defined in claim 1, and in which said vibratileportion is elongated and increases in depth at a substantially lstraightIline slope from both ends thereof to the longitudinal center portionthereof along all longitudinally extending lines 1 spaced inwardly fromsaid interconnecting portion.

4. An acoustic diaphragm of the type delined in claim l, and in whichsaid vibratile portion iselongated and increases in depth at asubstantially straight line slope from both ends thereof to thelongitudinal center portion thereof along all longitudinally extendinglines spaced inward- For example, diaphragms of rectangular shape.readily lend themselves to mounting behind lthe dashboards of'automobiles andthe like. By the practiceV of this inventionlarectangular-shaped diaphragm having good structural strength and havinggood sound reproducing or producing qualities may be readilyconstructed.

Also, it will be seen that by the practice of this invention arectangular-shaped diaphragm having a relatively large frontal area maybe alorded, and it has been found that with this .construction thevibratile portion 2 vibrates substantially as a unit at frequencies inthe audi- 'l ble range, and affords remarkably true reproductions of theoriginally produced sound waves in such a range.

ly from said interconnecting portion, and in which said -vibratileportion is substantially the same width through- .out its length, andlongitudinally slopes from a substantially frusto-conical transversecross-sectional shape at said nipple through a substantially ellipticaltransverse crosssectional shape, and then a substantially semi-circularytransverse,cross-sectional shape, to a rounded transversecross-sectional shape of less depth than a semi-circle.

References Cited in the file of this patent UNITED STATES PATENTS Bobber a1.V Jan- 2,1. 1958

